for \(\gamma _p=\frac{2(p-2)}{p}\) . Since \(2<p<4\) , we have \(\inf \limits _{ S(a_1)\times S(a_2)}I(u,v)=-\infty \) . In spirit of Bartsch and Soave in [1]}, we introduce the following Pohozaev set:
\(\mathcal {P}_{a_1,a_2}=\big \lbrace (u,v) \in S(a_1)\times S(a_2) : P_{a_1,a_2}(u,v)=0\big \rbrace .\) 
